1. Field of the Invention
The present invention relates to an optical device for a semiconductor laser, and a semiconductor laser device in which an optical device and a semiconductor laser chip are formed in an integrated manner. More particularly, the present invention relates to a semiconductor laser device having a small size and a stable structure in which there is no wavelength shift of a light source. In addition, the present invention relates to a method of producing such an optical device and to a method of producing such a semiconductor laser device.
2. Description of the Related Art
A semiconductor laser device is small and light, so that it is widely used as a light source for an optical disk apparatus and the like. An exemplary conventional semiconductor laser device is shown in FIG. 4 (see "SHARP Semiconductor Data Book", p. 17, 1992).
The semiconductor laser device shown in FIG. 4 includes a semiconductor laser chip 1, a cap 3, and a stem 8. When a current is caused to flow through the semiconductor laser chip 1, laser light 4 is emitted from an emitting end face 9 of the semiconductor laser chip 1. The laser light 4 is further emitted to the external of the semiconductor laser device through a glass plate 5 which is provided in a laser light emitting portion (opening) 11. The laser light 4 can be applied to various optical systems. A monitoring photodiode 10 is mounted on a member for supporting the cap 3 and the stem 8. The monitoring photodiode 10 monitors the intensity of laser light emitted from another end face of the semiconductor laser chip 1 opposite to the emitting end face 9.
The conventional semiconductor laser device as shown in FIG. 4 has a problem in that the oscillation wavelength may vary as the temperature of the laser chip changes.